1. Loop Offset
It’s a fantastic way to quickly adjust repetitive movements.
The index expression is not rocket science, but in After Effects it is an extremely strong instrument. The index expression essentially returns a value depending on the timeline position of the layers. The 4th layer in a timeline, for instance, returns a value of 4.
The index expression’s true power arises by using it as a manner of offset values. Whether you link it to a random seed or use it as a manner to offset a shape layer’s position, there are many possible ways to use this expression.